Carpenter s square



(No Model.) n

` J. P. DEEGAN.

CARPENTERS SQUARE.

No. 566,970. Patented Sept. 1 1896.

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JOSEPH P. DEEGAN, OF ST. LOUIS, MISSOURI.

CARPENTERS SQUARE.

SPECIFICATION forming part of Letters Patent No. 566,970, dated September 1, 1896.

Application filed January 3l, 1896. Serial No. 577,488. (No model.)

To all whom t may concern:

Be it known that I, JOSEPH P. DEEGAN, a citizen of the United States, and a resident of the city of St. Louis, in the State of Missouri, have invented a certainnew and useful Improvement in Carpenters Squares, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specilication.

My invention relates to an improvement in carpenters jointed squares.

My invention consists in features of novelty hereinafter fully described, and pointed out in the claim.

Figure I is a side View of my improved square. Fig. II is an enlarged detail side View of the angle portion of the square. Fig. III illustrates a longitudinal section taken on line III III, Fig. II. Fig. IV illustrates a cross-section taken on line IV IV, Fig. II. Fig. V illustrates a cross-section taken on line V V, Fig. II. Fig. VI illustrates a cross-section taken on line VI VI, Fig. II. Fig. VII illustrates a section taken on line VII VII, Fig. V, showing a modified form of the securing device employed to retain parts of a square together.

In the drawings, l designates the long arm, and 2 the short arm, of a carpenters square. On the long arm l is a right-angle extension 3, formed with a dovetail mortise 4, in which fits a dovetail tenon 5 ofthe short arm 2. The extension 3 is also formed with beveled side undercuts Lia, gradually flaring inwardly, which receive corresponding side bevels 2a on the tenon. It is important to retain the greatest amount of material possible in the short arm 2 at the juncture of the short arm and tenon, and for this reason I form the tenon of greater thickness at said juncture than at its outer end, the tenon gradually increasing in depth (as is clearly illustrated, especially in Fig. III) from its outer end to the juncture at its inner end. The central portion of the extension 3 is gradually reduced in height in the reverse direction from the outer end of the tenon 5, and therefore while the two parts are joined together they are connected by what is known as a scarfjoint, and a iiat surface is produced on each side of the square. The inner end of the extension is formed with a transverse bevel 3, fitting in a transverse bevelshaped undercut 2b.

For the purpose of retaining the two arms of the square in proper relation to each other when placed together I employ a set-screw 6, which is inserted through the edge of the eX- tension 3 and enters into an opening in the tenon, (see Fig. V,) and when in such position securely holds the tenon from movement in the dovetail mortise 4. WVhen it is desired to take the squ are apart, the screw 6 is turned outward until it has been turned out ofV engagement with the tenon, when the tenon can be readily slipped from the mortise, and the two arms of the square will be separated.

In Fig. VII I have shown a modified form of retaining device, in which a trip-arm 7 is pivoted in a recess 9 to a pin 8 at the same location as that of the screw 6. The point of the arm 7 is adapted to engage with a notch in the edge of the tenon 5fL and is normally held in engagement by a spring l0, located under the rear end of the arm.

I claim as my invention- A carpenters jointed square comprising a long arm and a short arm; the long arm having a right-angle extension formed with a longitudinal dovetail mortise which gradually increases in height from its outer end, with gradually inwardly-daring beveled undercuts at the sides thereof, and with a transverse bevel at its inner end, and the short arm havinga transverse bevel-shaped undercut, anda longitudinal dovetail-shaped tenon gradually increasing in depth from its outer end, formed with gradually inwardly-widening bevels at the sides thereof; substantially as described.

J. P. DEEGAN.

In presence of- E. S. KNIGHT, N. FINLEY. 

